Patent PL-83234-B1 (PL)
Title: Process and apparatus for joining a tubular thermoplastic container jacket,by means of ultrasonics,to a thermoplastic end cap to form a liquid-tight seal[us3824138a]
IPC: H01G9/10
Filed: 1971-12-09
Abstract: 1322868 Seaming non-metallic sheet material TELEPHON-UND TELEGRAPHEN-FABRIKSAG KAPSCH & SOHNE IN WIEN 1 Dec 1971 [10 Dec 1970 5 April 1971] 55794/71 Heading B5K [Also in Division H1] A top or bottom cap 5 of thermoplastic material is ultrasonically welded to a thermoplastic container body 6 by inserting the cap 5 into the open end of the body 6 until the body rim 6a projects beyond the cap 5 ; advancing an axially vibrating sonotrode 10 against the rim 6a to soften the rim 6a and roll it radially inwards over the rim of the cap, the softened rim 6a becoming trapped during this movement in a closed chamber formed at least partly by the sonotrode 10 and the cap 5; and advancing the sonotrode 10 further thereby applying a welding pressure to the softened material of the rim 6a. In one embodiment, Fig. 1, a top cap 5 is welded to a body 6 to form a primary galvanic cell having a carbon rod 1, an electric contact piece 2, a cast composition 3 and a zinc pot 4. The sonotrode 10 has an annular recess 11 formed by cylindrical walls 11a 11c merging into a thrust wall 11b perpendicular to the lower face 12 of the sonotrode. The diameter of the wall 11a is the external diameter of the body 6. The lower edge of the wall 11c terminates in an edge 13 which, when the sonotrode is lowered, enters an annular channel 5b in the cap 5 and a conical surface 14 engages the inner edge of the channel 5b to enclose the welding zone in an annular chamber. The outer edge of the sonotrode extends downwards in the form of a skirt 16 having a rounded mouth 18. Preferably, the sonotrode is energized before or during its downward movement so that it is already vibrating when it slides over the outer surface of the body 6. In a modification, Figs. 3-6 (all not shown), a low pressure polyethylene bottom cap is welded to a high pressure polyethylene body. In another embodiment, Fig. 7, the sonotrode contains a member 20 to thrust the cap 5 downwards in the body 6 before the welding operation. The member 20, which may be made of steel, is attached to a sonotrode part 10a by a resilient rubber connector 17 and is guided for sliding movement by annular collars 20a, 20b having anti-friction material, e.g. polytetrafluoroethylene, thereon. In use, on lowering the sonotrode, the member 20 first contacts the cap 5 and an annular edge 20c thereof penetrates into the channel 5b and a conical surface 20d thrusts against the inner edge of the channel 5b. The connector 17 is deformed and welding is effected. Air vents 10f, 20f are provided. In a modification (not shown), the connector 17 is omitted and the member 20 is actuated hydraulically or pneumatically independently of the sonotrode. In a further embodiment, Fig. 9, an elastically deformable top cap 5 has been welded to the body 6 and the cell is mounted upside down on a ring 30. When a downward thrust is applied to a bottom cap 7, containing an embedded electric piece 8 and positioned in the body 6, by a sonotrode 10 somewhat similar to that of Fig. 7, the cap 5 is deformed, Fig. 10 (not shown).
[GB1322868A]